Transmitting device for micro oscillations



B. MEIDELL.

BIRGER MEIDELL, OF CHRISTIANIA NORWAY.

TRANSMITTING DEVICE FOR MICRO OSCILLA 'IIONS Specification of Letters Patent.

Patented Mar.30, 1920.

Applieatign filed March 8, 1918. Serial No. 221,192.

To all whom it may concern:

Be it known that I, BIRGER MEIDELL, a subject of the King of Norway, residing at Christiania, in the Kingdom of Norway, have invented certain new and useful Improvements in Transmitting Devices for Micro Oscillations; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters or figures of reference marked thereon, which form a part of this specification.

The present invention has for its object a transmitting device for micro oscillations, and the object of the invention is to obtain a more effective transmission than by the apparatuses at present in use in microphones, gramophones, etc.

It is known to construct microphones comprising two simultaneously' actuated diaphragms with a common intermediate grain box so that the effect of the sound is doubled. Further it is known to increase the effect of the microphone by connecting the diaphragm with the carbon grain box by means of a system of levers. known however it is difficult to make lever systems of this kind effective with regard to the reproduction of weak sound waves.

The present invention consists in a combination of the two systems above referred to, said-combination being carried out in such a manner, that the two effective dia--" phragms are connected to a single lever mechanism at points so located that all bearing pressure in the pivot point of the lever is eliminated or at least reduced to a minimum, so that all desired transmission of micro movements to the stationary parts of the apparatus is obviated, whereby even the weakest oscillations reach the working part of the mechanism without loss of energy. The invention may practically be carried out in such a manner that the lever system is not mounted in a stationary pivot and is free to oscillate on one (or more) lmaginary axes.

In a system of this kind a number of Though it is well advantages is obtained and the efficiency of the apparatus is materially increased.

On the drawing a practical embodiment of the invention is illustrated diagrammatically. I v

A and B are two diaphragms, C and D carbon grain boxes and E, F the movable electrodes of the same, said electrodes being mounted at opposite ends of lever G, which is connected with the diaphragms in any suitable manner for instance as illustrated on the dr'awing'by means of short columns H, I .pivotally connected to lever G. The

dotted lines indicate how a mouth piece or the like may suitably be adapted to a microphone as above described.

As will be noted the lever G if acted uponequally by both diaphragms will oscillate about a point 0, whereby the micromovements of the diaphragms are multiplied at both ends of'lever G, so that the electrodes will actuate the carbon gi'ains effectively.

-It is obviously not necessary to place a carbon grain box at each end of lever G, even a one-sided arrangement will givea similar result, and by adapting the invention I for microphones a one-sided arrangement will evidently be resorted to.

I claim 1. In an apparatus for transmitting micro-oscillations, two simultaneously actuated oscillating members and a lever system pivoted only to said oscillating members and oscillating about a point between said oscillating members.

2. In an apparatus for transmitting micro-oscillations, a pair of parallel diaphragms, a pair of carbon boxes each "parallel to a diaphragm, an electrode. in each box, a lever whose ends are in contact with the electrodes and means to connect the diaphragms 'pi'votally to said lever on opposite sides of its axis of oscillation.

In testlmony that I claim the foregoing 

